re #28 add services for Language model
re #28 add unit tests for the services of Language model
re #28 add select box for the language in the user properties template
re #28 add missing DBSession.add function for some attributes in the
database initialization script
re #28 add a loop in the language select box to display all the
languages
re #28 fix service name bug in the settings user view
re #28 correct name label error in a language object of the database
initialization script
Merge pull request #51 from jean553/fix_28B

Fix 28 b - SellerUser settings - Add language selection box in the settings user template